On a wim, I just created a user style to hide graphs on the dashboard. If you’re on Chrome you can install the style using the Stylish plugin, and I’m sure Firefox has something, too.
Top tip: make use of in-browser user profiles to keep private things private. Even better if it’s not your usual browser.
e.g. in Edge on macOS, I’ve got a profile that’s only for my online banking. No extensions enabled, little risk of cross-site scripting attacks. I do the same to keep my various work-related google and microsoft logins segregated.